Air-cooled internal-combustion engine



R. KRONENBERG. AIR COOLED INTERNAL COMBUSTION ENGINE;

APPLICATION FILED JULY 27. 1920'.

Patented July M, 11922.

- ntremascot-En I INTERNAL-COMBUSTION Enema.

Specification of Letters Patent.

Patented July 11, 1922.,

Application filed July 27, 1920. Serial No. 399,417.

To all whom it may concern Be it known that I, RUDoLF Knonnnnnne, a citizen of the German Republic, residing at lVilhelmstrasse, Ohligs, Germany, have invented certain new and useful Improvements in Air-Cooled Internal-Combustion Engines, of which the following is a statement.

It has been the object of the inventor to obtain the necessary cooling of combustion engines by means of air only, thus without employing water. For this purpose he has already suggested a special method of cool ing the inner cavity of the hollow piston, so as to conduct the cooling air from inside to the critical points. The already known cooling of the cylinder from outside, combined with this method ofcooling the hollow piston will in many instances be sufficient to allow of dispensing with water-cooling. The inventor has now gone still further. He found that in the proximity of the valves a comparatively large amount of heat may accumulate, which will cause a considerable heating of the cylinder-head situated close by, and which may, eventually, also affect the piston-packing. It is the object of the present invention to conduct also this heat off at such a time and in such a manner that it cannot accumulate.

According to the present invention the communication passage leading from the valves to the cylinder is surrounded by a hollow space, which communicates with the atmosphere in such a manner that the same can flow through this cavity and thereby keep the wall of the said passage, and, altogether, the valve casing cool. By thus keeping the wall of the valve casing cool, the heat is conducted away from the cylinderhead. This effect may be further increased by a further cavity being interposed between the abutting surfaces of the valve casing and the cylinder-head, respectively, through which cavity the .air is likewise circulated. In both cases the natural draught may be utilized, or an artificial draught may be produced in known manner by means of a fan or the like.

In the accompanying drawing a constructional form of the invention has been shown by way of example. I Fig. 1 is a horizontal section through the valve Casing.

Fig. 2 is a top view of the same.

Fig. 3 is a vertical section on the broken line CD in Fig. 1.

Fig. 4 is a vertical section through the valve seats.

The part of the valve casing surrounding the valve seats is in a stationary position at the side of the cylinder, so that the air will by itseli circulate around it and it is thus cooled, so much the more as it is fitted with radiator webs.

The passage or, which leads from the valves to the cylinder head, 1) (shown in the drawing by dotted lines) is surrounded by a cavity c, which by means of openings (l, d communicates with the atmosphere. The air which, in consequence thereof, and under force of the natural or an artificial draught circulates through the cavity 0, will cool the walls of the passage a, but also the inside walls of the valve casing so that the heat coming from the cylinder-head will there, by the metal of the valve casing be transferred to the air circulating through the cavity 0. Between the flange surface of the cylinder head I) and the abutting surface of the valve casing an annular cavity 7 may be provided, which through holes h, h likewise allows of a circulation of the air through it. This air will, in a particularly effective manner carry off a great part of the heat immediately after its production.

In Fig. 1 the valve casing is shown fitted between two cylinders, communicating to the left with the cylinder head 6.

The cavities for carrying oil the heat by the air circulating therethrough may, obviously, be arranged in various ways. In place of the one cavity 0 also several cavities may be employed, which may be separate from each other and each communicate independently with the atmosphere. or which may also communicate with each other, so that the same current of air passes through all of them.

Although the present invention is chiefly intended for such motors, which operate without watercooling, it is obvious that the invention may also be employed with motors which are provided with water cooling.

I claim:

In an internal combustion engine, a valve rounding said passage and communicating In testimony whereof I have hereunto set with the atmosphere adapted for the ciroulamy signature in the presence of two subscribtion of atmospheric air therethrough and ing witnesses.

around the said passage by natural draught, DR. RUDOLF KRONENBERG. an annular cavity between the said casing Witnesses: and head, and openings communicating with AUG. BAUER,

ENGELS;

said last-named cavity. 

